1. Technical Field
This disclosure relates generally to digital video or image processing and display.
2. Description of the Related Art
Various devices including but not limited to personal computer systems, desktop computer systems, laptop and notebook computers, tablet or pad devices, digital cameras, digital video recorders, and mobile phones or smart phones may include software and/or hardware that may implement video processing method(s). For example, a device may include an apparatus (e.g., an integrated circuit (IC), such as a system-on-a-chip (SOC), or a subsystem of an IC), that may receive and process digital video input from one or more sources and output the processed video frames according to one or more video processing methods. As another example, a software program may be implemented on a device that may receive and process digital video input from one or more sources according to one or more video processing methods and output the processed video frames to one or more destinations.
As an example, a video encoder may be implemented as an apparatus, or alternatively as a software program, in which digital video input is encoded or converted into another format according to a video encoding method, for example a compressed video format such as H.264/Advanced Video Coding (AVC) format, or H.265 High Efficiency Video Coding (HEVC) format. As another example, a video decoder may be implemented as an apparatus, or alternatively as a software program, in which video in a compressed video format such as AVC or HEVC is received and decoded or converted into another (decompressed) format according to a video decoding method, for example a display format used by a display device. The H.264/AVC standard is published by ITU-T in a document titled “ITU-T Recommendation H.264: Advanced video coding for generic audiovisual services”. The H.265/HEVC standard is published by ITU-T in a document titled “ITU-T Recommendation H.265: High Efficiency Video Coding”.
In many systems, an apparatus or software program may implement both a video encoder component and a video decoder component; such an apparatus or program is commonly referred to as a codec. Note that a codec may encode/decode both visual/image data and audio/sound data in a video stream.
Generally defined, dynamic range is the ratio between the largest and smallest possible values of a changeable quantity, such as in signals like sound and light. In digital image and video processing, conventionally, digital images (e.g., video or still images) are captured, rendered, and displayed at a limited dynamic range, referred to as standard dynamic range (SDR) imaging. In addition, images are conventionally rendered for display using a relatively narrow color gamut, referred to as standard color gamut (SCG) imaging. Extended or high dynamic range (HDR) imaging refers to technology and techniques that produce a wider range of luminance in electronic images (e.g., as displayed on display screens or devices) than is obtained using standard digital imaging technology and techniques (referred to as standard dynamic range, or SDR, imaging). Many new devices such as image sensors and displays support HDR imaging as well as wide color gamut (WCG) imaging. These devices may be referred to as HDR-enabled devices or simply HDR devices. At the same time, many video capture devices and display devices may not directly support HDR imaging and/or WCG imaging.